In the prior art, it is generally known to construct a foldable rake that includes a trolley adapted for connection to a tow vehicle. The foldable rake includes rake arms carrying a number of rake elements (e.g. rake wheels, etc.) which are operable to direct crop material inwardly as the rake is pulled by the tow vehicle across the field. An example of a foldable rake is illustrated in U.S. Pat. No. 6,314,710 to Tonutti. The '710 patent discloses a foldable rake that includes a cylinder assembly in combination with an actuator configured to extend and retract along a longitudinal axis of the rake in moving one or more of the rake wheels between an inoperative and an operative position.
It is an object of the present invention to provide a vertically folding rake assembly that includes a vertically movable linkage arrangement configured to move the rake elements between a raised, inoperative position and a lowered, operative position. It is a further object of the present invention to provide a suspension-type support arrangement for the rake arms of a rake, in which the rake arms are mounted to a support member that is pivotal about a vertical axis. It is a further object of the invention to provide a rake arm suspension arrangement that includes a pivot connection for providing pivoting movement of each rake arm, which carries the rake elements, about a generally horizontal pivot axis. It is a further object of the invention to provide a counterbalanced biasing arrangement in association with the rake arm suspension arrangement for biasing the rake arm toward a centered position.
In accordance with one aspect of the invention, one embodiment of a rake includes a trolley and a rake arm suspension support arrangement interconnected with the trolley and movable between a raised position and a lowered position. The rake arm suspension support arrangement includes a pair of linkages and a pair of rake arm supports. The linkages are movable in a generally vertical plane. Each rake arm support is pivotally interconnected by a bracket with one of the linkages for movement about a generally vertical pivot axis. A preferred bracket generally includes a pair of plates configured to receive each linkage therebetween. A rake arm carrying a raking means or element (e.g., a rake wheel) is suspended from each rake arm support by a vertical support member.
Each rake arm support includes a horizontal support member interconnected with the vertical support member. The horizontal support member includes a collar that defines the generally vertical pivot axis of the vertical support member. The rake arms are generally suspended from a lower end of each of the vertical support members.
The rake arm suspension arrangement for suspending each rake arm from the trolley further includes a pivot connection for providing pivoting movement of the rake arm about a generally horizontal pivot axis. The pivot connection includes a horizontal pivot pin in combination with a pivot plate pivotably mounted to the horizontal pivot pin. The lower end of each of the vertical support members includes a slot to receive the pivot pin, and the pivot plate is fixed to the rake arm. This arrangement allows the rake arm to pivot about a horizontal pivot axis defined by the pivot pin.
The rake arm suspension arrangement further includes a counterbalanced biasing arrangement associated with each rake arm for biasing the rake arm toward a centered position. The counterbalanced biasing arrangement includes a first biasing assembly and a second biasing assembly positioned on opposite sides of each vertical support member. Each of the first and second biasing assemblies is connected by a bracket to the vertical support member. Each first and second biasing assembly includes a spring that extends generally parallel to the vertical support member between the bracket and the rake arm. The first and second biasing assemblies each further includes a spring compression adjustment feature, to vary the biasing force applied by the spring to the rake arm. The spring compression adjustment feature may include a bolt and a locking nut securing the bolt to one of the first and second brackets. The bolt is configured to extend into an interior defined by one of the springs. The spring compression adjustment feature further includes a tightening nut and a washer located between the tightening nut and the spring. The tightening nut is received by and configured to move along the bolt to adjust the position of the washer and the end of the spring, to thereby selectively adjust the compression of the spring. The lower end of the spring may be secured by a plate to the rake arm.
The rake preferably also includes a front rake wheel mounted at a forward end defined by each rake arm. The front rake wheel is movable between a raised, inoperative position and a lowered, operative position relative to the rake arm in accordance with crop conditions. A front rake arm support member carries the front rake wheel on each of the rake arms. The front rake arm support member is pivotally connected by a stub shaft that is pivotably mounted to a sleeve located at the front end of the rake arm. A coupling is received through openings in the stub shaft and aligned openings in the sleeve so as to secure the front rake wheel in the raised, inoperative position or the lowered, operative position relative to the rake arm.
The rake preferably also includes a lifting and lowering means interconnected with the rake arm suspension support arrangement for moving the one or more rake arms between a raised, inoperative position and a lowered, operative position. The lifting and lowering means includes a vertically movable actuator arrangement interconnected between the trolley and each the linkages. The vertically movable actuator arrangement includes an upright member and a guide member received within a passage defined by the upright member in a telescoping manner. The upright member may be mounted between first and second mounting plates carried by the trolley. The guide member is configured to move in a vertical direction relative to the upright member.
The vertically movable actuator arrangement also includes an operating mechanism for moving the actuator arrangement in a vertical direction. In one form, the operating mechanism is a cylinder assembly having a cylinder end and a rod end that is extendible and retractable from the cylinder end. The cylinder end of the cylinder assembly is connected to the trolley, and the rod end of the cylinder assembly is connected by a pin to the guide member such that extension and retraction of the cylinder assembly causes extension and retraction of the guide member in a telescoping manner and in a vertical direction relative to the upright member. The cylinder end of the cylinder assembly may be secured by a mounting bracket connected to one of the plates between which the upright member is located. A reinforcing bar can be attached between the mounting bracket and the trolley to add rigidity to the support structure. The vertically movable actuator arrangement further includes front and rear pairs of actuating links, each of which has a lower end pivotably connected to one of the linkages. An upper end of each of the actuating links is connected to the rod end of the cylinder assembly via a pin. The actuating links include overlapping slots that receive the pin therethrough, such that extension of the cylinder assembly lifts the upper end of each of the front and rear actuating links and the pair of linkages attached thereto.
The rake further preferably includes a pair of control members, each of which is interconnected between the trolley and each rake arm support. The pair of control members are configured to move the pair of rake arm supports apart from one another when the linkages are lowered, and to move the rake arm supports together toward one another when the linkages are raised.
The rake arm suspension arrangement further includes a windrow width adjustment arrangement for varying the angle defined between the rake arms when the rake arms are in the lowered, operative position. The adjustment arrangement may include a turnbuckle assembly interconnected with each of the pair of rake arms, which is configured such that adjustment of a length of the turnbuckle assembly selectively varies an angle defined between the rake arms when the rake arms are in the lowered, operative position. The vertical support of the rake arm suspension arrangement includes a head disposed above the collar of the horizontal support member. The head is connected to an arm extending radially outward from the collar. A first coupling of the turnbuckle assembly is connected at the arm and a second coupling of the turnbuckle assembly is connected at the horizontal support member. The arm includes a first opening disposed radially outward from a second opening relative to the head. The first coupling of the turnbuckle assembly is connected to the arm by a pin inserted in the first opening, which allows the rake arms to pivot apart from each other when the rake arms are moved to the lowered, operative position. Alternatively, the first coupling of the turnbuckle assembly is connected by the pin inserted in the second opening when the rake arms are positioned in the raised, inoperative position. The collar includes a tab having an opening generally aligned with the second opening of the arm, such that pin engages the tab in a manner that restrains movement of the rake arms when the rake arms are in the raised, inoperative position.
In accordance with another aspect of the invention, a method of operating a rake for movement between a transport position and an operating position for creating a windrow of cut crop material in a field is provided. The method includes the steps of actuating a vertically movable linkage arrangement connected so as to selectively raise and lower a suspension arrangement in support of one or more rake arms carrying rake means; and selectively securing the suspension arrangement in a raised, inoperative position or positioning the suspension arrangement in a lowered, operative position. The method can further include the steps of actuating the vertically movable linkage arrangement by operation of a cylinder assembly configured to move the vertically movable linkage arrangement in a vertical direction; and pivoting a horizontal support of the suspension arrangement about a generally vertically axis so as to move the suspension arrangement relative a central axis of the rake. The method may include locking a rake arm and a vertical support carrying the raking means so as to restrain pivoting movement of the rake arm while the rake is in the inoperative position. The rake arm is moved to the lowered, operative position by retracting the cylinder assembly so as to lower the suspension arrangement and associated raking means; pivoting the suspension arrangement in an outward direction from the central axis of the rake while lowering the suspension arrangement; and pivoting a rake arm in support of the raking means to an open position for creating the windrow of cut crop material as the rake is moved along the ground. The method may further include engaging the suspension arrangement with a cushioned stop member attached to a trolley in support of the suspension arrangement and the raking means when the rake arm is moved to the lowered, operative position.
While all of the features of the present invention can be incorporated together into a rake to enhance operation, it is understood that the one or more of the features of the invention may be utilized separately from each other or in combination with other rake features, and that each functions to enhance rake operation on its own.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.